Alloy



weight of iridium,

Patented Mar. 22,1932

UNITED STATES PATENT OFFICE ROMAINE G. WALTENBERG, OF BOSELLE, HENRY EDWIN HOLBEOOK, OF IB'VINGTON, AN D BERT BRENNER, OF ELIZABETH, NEW JERSEY, ASSIGNOBS TO THE B. A- WILSON COMPANY, OF NEWARK, NEW JERSEY, A. CORPORATION 01 NEW JERSEY ALLOY No Drawing.

This invention relates to alloys and is concerned moreparticularly with novel alloys to be used primarily for such urposes as contact points in devices for ma 'ng and break- 5 ing electrical circuits.

In electrical devices of the type described, for example, voltage regulators, numerous alloys have been used for contact'points, such as alloys of platinum with about 30% by and binary alloys of platinum-metals including approximately equal percentages of platinum, iridium, osmium, rhodium, ruthenium, and palladium. Such alloys, however, with the exception of platinum-palladium and platinum-rhodium with about of rhodium by weight are subject to the important disadvantage of being unworkable by swaging, rolling or drawing. All these alloys, therefore, have to be machined or ground to the desired shape, and this necessitates difiicult and expensive operations in the fabrication of the alloys to commercial forms, such as contact points.

The present invention is accordingly directed to the provision of allo s particularly useful for contact points WhlCl'l givebetter results in service than the alloys now commonly used and which are workable by swaging, rolling, and drawing, so that the contact points and other articles can be made from them without the expensive grinding and machining operations heretofore required.

We have found that the desired results may be obtained by employing iridium as the principal constituent of the alloys, using that metal 1n amounts greatly in excess of present practice. Alloys contamin from 7 0% to 90% by weight of iridium with the remainder made up of one or more .of the metals platinum, palladium, rhodium and ruthenium fulfill the requirements mentioned, although it was to be expected from the rim work done in this field, that an increase in the amount of iridium would make working more difiicult. Our experiments have made clear that this is not the case and in addition to improved workability, anall'oy containing to 90% iridium with the remainder made u of one or more of the metals platinum, palladium,

50 rhodium and ruthenium is of greater stabili- -tures Application filed March 6, 1981. Serial No. 520,708.

ty when used for contact purposes, the surface does not readily become oxidized or corroded, loss of the contact material due to mechanical wear or vaporization is reduced, and building up of one point by transfer thereto of material from the other is also lessened.

A superior alloy of the type described is one which consists of iridium and 20% platinum by weight, although the proportions of the ingredients may be varied within the range mentioned.

What we claim is:

1. An alloy containing iridium to the amount of about 70% and the remainder made up of one or more of the metals platinum, palladium, rhodium, and ruthenium.

2. An alloy containing iridium varying from about 70% to and the remainder made up of one or more of the metals platinum, palladium, rhodium, and ruthenium.

3. An alloy containing approximately 80% iridium and the remainder platinum.

4. An alloy containing iridium to the amount of about 70% to about 90% and the remainder platinum.

5. An alloy containing, iridium to the amount of about 70% to about 90% and the remainder rhodium.

6. An alloy containing iridium to the amount of about 70% to about 90% and the remainder palladium.

In testimony whereof we aflix our signa- ROMAINE e. WALTENBERG. HENRY EDWIN HOLBROOK. BERT BRENNER. 

